Display technologies are integral to most electronic devices, being used both for watching media such as television or films and for graphical user interfaces for computers, mobile phones and other electronic devices.
In recent years, the use of three-dimensional technology in such displays has been gathering momentum. In particular, the use of such three-dimensional technologies for television broadcasting has become of particular interest. The basic technology behind three-dimensional imaging is well known and well established, dating back to the early 1900s. Three-dimensional moving images have also been around for many years, but have not yet been utilised much in consumer electronic devices.
Three-dimensional imaging works by tricking the eye into perceiving depth information through two or more images. There are various established techniques for achieving this, the most popular of which utilise two images and are called stereoscopic techniques. Stereoscopic techniques utilised for moving images such as television involve displaying each image to be viewed by the viewer as two images; one image arranged to be viewed by the right eye and one image arranged to be viewed by the left eye.
The left and right images differ slightly such that when they reach each eye the viewer can extract depth information from the images. Such depth information is created using two (slightly) different images. Each portion of the left and right images contains views of objects that are captured from subtly different perspectives. As a result, the offset of the views differ by a certain number of pixels, in accordance with the depth to be perceived by the viewer.
In order to allow for such a three-dimensional imaging technique to work, a mechanism is required to separate the images for the left eye from images for the right eye. There are several such techniques. One technique is to display the images alternately in quick succession and use a mechanism synchronized to the display to control which eye sees the display only when the appropriate image is displayed. Other techniques include the use of passive polarization glasses and a polarized display, which allow each eye to see part of the screen for all of the time.
When broadcasting three-dimensional images, for example as part of television broadcast, the perception of depth that is associated with three-dimensional images is achieved by a pair of similar two-dimensional images captured from slightly different perspectives and thus slightly offset from each other. The offset of the two images, which in turn determines the perceived depth of the image, is determined in accordance with a fixed image size before transmission. For example, the depth may be determined for displaying on a 48-inch television. If the received television signal is then displayed on a 32-inch television, the image information will be scaled by ⅔rds for being displayed on the 32-inch television.